Contacting process



Sept. 18, 1945. M. M. MARISIC CONTACTING PROCESS Filed March 3, 1945 2Sheets-Sheet l INVENTOR MILTON M MAR/SIC GEL P511033 PROCESS/[VG Sept.18, 1945.

Filed March 3, 1943 2 Sheets-Sheet 2 5151 4701? S. U J2 i l FLl/f 45 7/a g grf U Q U a 61? fimfms U Q 1 awn El? U Q J7 J6 O 64 J5 U Q All? 401: k 5754! Q g \47 E 55mm?! JTEAM 5E4 67 5 VAPOR J4 asp/mm CHARGEINVENTOR Mil TON M MAR/SIC BY, Qua/411$ Patented Se t. is, 1945 UNITEDSTATES PATENT OFFICE Sooony-Vscnnm Oil Company,

Incorporated,

a corporation of New York Application March 3, 1948, Serial No. 471.808

5 Claims. (01. 106-52) This invention is directed to processes ofcontacting a fluid with a solid and is specifically concerned with theprovision a process utilizing a solid which may be of conventionalchemical composition but is of novel physical properties rendering itpeculiarly suitable to the purpose.

In many commercial processes it is found desirable to contact a fluidwith a solid to treat or modify either contacting material. The problemsof handling the contacting materials are similar in all such processesand adequate discussion is advantageously conducted in connection with atypical process. The vapor phase conversion of initial hydrocarbons tohydrocarbons of diilerent Properties in the presence 0! a solid catalystis such a typical process. Among the other processes to which theinvention is adapted. may be mentioned treatment oi water with seoliticsolids, etc. Catalytic hydrocarbon conversions are usually carried outby contacting the hydrocarbon, usually in vapor form and at high"temperature, with a contact mass composed of particles which themselveshave a catalytic eilect, or which are impregnated with or act as asupport {or other catalytic material 0! a nature appropriate to theresult desired. Such operations may contemplate, for example, theconversion of hydrocarbons of high boiling point to those oi lowerboiling point. or the polymerization 0! light or gaseous hydrocarbons toydrocarbons of higher boiling point. Other operations of like nature arecatalytic dehydrogenation, hydrogenation. alhrlation, aromatization,reforming, polymerization. desulmrizing, partial oxidatlonand similarconversions of hydrocarbon materials. The method of operation andapparatus herein disclosed are applicable to all such conversions. Ofthese operations, the vapor phase cracking of heavy hydrocarbons togasoline is typical, and this specification will lireinaiter discusssuch operations as exemplary, without, however. intending to be limitedthereby or thereto except by such limits as may appear in the claims.

Such catalytic processes generally make use of reaction chamberscontaining a ilxed body of catalyst or contact mass, through which thereaction mixture is passed, and in which, after the reaction has sloweddown to an uneconomic point, the contact mass is regenerated in situ.Buch processes are not continuous, and only attain continuity by theprovision of numerous reaction chambers which are alternately placed onstream and on regeneration. Likewise, it is difflcult to maintainconstant quantity and quality 0! product without numerous chambers andintricate' scheduling, due to the progressively decreasing activity ofcatalyst. This same feature,

with apparatus limitations, prevents, to a degree,

the use of catalyst. at a uniform high emciency level. Most of thesediiilculties may be avoided by the use of a method wherein the catalystor contact mass is handled continuously as well.

The catalyst of this invention is particularly well adapted to such aprocess, although advantages over previous catalysts are noted instationary bed operations.

This invention has for its preferred object the provision of a solidcontact material in spheroidal iorm tor a process of solid-fluidcontacting, wherein a continuously moving stream or fluid is contactedwith a continuously moving stream of spheroidal pellets tor the purposesof the process, in which the contact mass is used only at a.

high level oi eillciency, since the contact material is preferablycontinuously removed and regenerated, and then returned to thecontacting step. both operations being conducted under 5 controlledconditions.

In operations of this type, the term "gel" has been rather looselyapplied to include both true gels and gelatinous precipitates. Informing pellets of either, the gel or precipitate has been caused toform completely and then subjected to suitable operation for theformation of particles. These have not been particularly satisfactorybecause the particles obtained are not resistant to losses by shockbreakage and abrasion. The common operations include breaking a mass ofgel to fragmentary particles and screening to separate particles ofdesired size. This results in the production of a considerable amount oifines which are a loss since they cannot be used in present catalyticequipment. In

some cases, the wet gel is molded. This requires expensive moldingequipment and costly cleaning of molds. It is also proposed (ReissuePatent 21,690) to separate the mass into two parts, one

oi which is dried and crushed and the other used wet to bind the crushedportion in a molding operation which involves the usual objections tomolding.

The present catalyst is prepared by a method which eliminates theheretofore necessary step tact bed is utilized, whether it be of thestationary or the moving (or flowing) type of bed. spherically-shapedparticles can pack only in a uniform manner, hence, channeling of vaporsor fluids flowing through this type of bed is impossible. For anoperation in which a moving or flowing) contact bed is employed, pelletsof a spherical shape afford unique flow characteristics.

This process of forming the pellets involves continuously contactingwithin an enclosed mixmg chamber such as an injector or nozzle mixer,streams of reactant solutions of such concentrations and proportionsthat no gelation occurs within the mixer, but only at somepre-determined time after leaving the mixer, and under such conditionsof flow that each stream is completely and uniformly dispersed withinand throughout the other at the instant of contact. The resultingcolloidal solution is elected from the mixer through an orifice ororiflces of suitable size so as to form globules of the solution whichare introduced into a fluid medium where the globules of the colloidalsolution set to a gel before they pass out of that medium. The fluidmedium may be any liquid or combination of liquids which is immisciblewith water such as. for example, petroleum naphtha, kerosene,hydrocarbon oils. etc.

There are two alternative method of operation which are dependent uponthe density of the fluid employed. When the density of the fluid islower than that of water, the fluid is supported over a. layer of waterand the colloidal solution from the mixer is introduced at the top ofthe column of fluid: the height of the latter and the gelation timebeing adiusted so that gelation occurs within the fluid and before theglobose particles reach the water surface. For a fluid more dense thanwater, the procedure is reversed; the colloidal solution is ejected intothe bottom of the fluid, the globules rise up through the fluid, gel andpass into a layer of water which conducts the gel away for processing.

The shapes of the formed gel are dependent upon the rate at which theglobules of the colloidal solution travel through the water-immiscibleliquid; while the rate of movement of the globules depends upon therelative density and viscosity of the fluid medium employed. If thelatter medium has a low viscosity and a density far removed from that ofthe colloidal solution, the glolbules of the latter solution will travelrapidly, hence, the gel pellets will assume flat or disc-like shapes.Examples of liquids in which pellets of this type may be produced arebenzene, carbon tetrachloride, or petroleum naphtha. A water-immisciblefluid medium having a high viscosity or a density close to that of thecolloidal solution will effect slow movement of the globules ofthe'latter solution and thus form spherically-shaped gel pellets. It isapparent from the above description that gel pellets of any shape,varying from flat-like discs to perfect spheres, may be manufactured bychoice of a water-immiscible fluid medium having the proper density andviscosity.

The success of this process is due to the fact that the gelation timefor a large number of materials can be controlled very accurately.

I have studied the preparation of man gels in which silica is thepredominant component and found that the gelation time can be controlledso that the invention described above may be utilized in theirpreparation. The following is a list of the gels I have prepared by themethods described herein: silica gel, silica-alumina, silicastannicoxide, silica-eerie, silica-thoria, silicaalumina-thoria,silica-alumina-stannlc oxide, silica-almnina-ceria, silica-zirconia,silica-zirconia-alumina. Further, the methods described herein may beextended to the preparation of many other types of gels.

The time of gelation is dependent upon temperature, pH andconcentrations of reactants. The higher the temperature, the shorter thetime of gelation. At flxed concentrations of reactants the gelation timeincreases with decrease in pH provided the pH is within the limits ofthe invention. When the temperature and pH are constant, the gelationtime decreases as the reactant solutions are made more concentrated.Considerations controlling gelation time are discussed in detail in mycopending application Serial No. 461,455, flied October 9, 1942.

Briefly, the invention contemplates a pellet of generally roundedoutline having uniform porosity, a hard surface and unusually highcrushing strength. These pellets are better suited to stationary bedoperation than conventional molded pellets because of their highresistance to breakdown in transportation and use; but their advantagesare achieved to a. very high degree when used in continuous processesinvolving constant exposure to forces tending to abrade and crush thepellets.

Other objects and advantages will be apparent from the detaileddescription below when considered in connection with the attacheddrawings wherein:

Figure 1 shows apparatus for use in preparing the catalyst;

Figures 2 and 3 show modified types of mixing nozzles for the apparatusof Figure 1;

Figure 4 is a modified type of apparatus for forming the pellets;

Figure 5 is an illustration in vertical section of apparatus forcontinuous catalytic conversion of hydrocarbons; and

Figure 6 is a diagrammatic showing of a plant unit including auxiliariesfor the process.

Referring to Figure l, a mixing nozzle, indicated generally at Iii, ismounted at the top of a column of water-immiscible fluid in a tank H. Atthe bottom of tank H is a layer of water which forms an interface l2with the column of said fluid. Water is continuously supplied throughinlet I3 and withdrawn through outlet ll. The interface at I! ismaintained by properly adjusting the height of conduit 9 in correlationwith the density of the fluid medium and the rate at which water issupplied at i3. Vent It prevents siphoning action. The flow of watercarries away the gel pellets through outlets H and 8 to suitable washingand treating stages. The water in which the pellets are carried away isitself a washing medium and may include any desired treating material toact as a treating stage.

The colloidal solution from which the pellets are formed is made up andadmitted to the column of fluid by the mixing nozzle ll. Preferably, theapparatus will include a plurality of nomles ill in order to increasethe capacity of the unit, but only one is shown here for purposes ofsimplicity. The nozzle It includes means for completely dispersing twosolutions in each other and admitting a continuous stream of theso-formed colloidal solution below the surface IQ of thewater-immiscible fluid, wherein the stream of the colloidal solutionbreaks up into globules. The

assasas colloidal solution or globules thereof may be dropped on thesurface of the fluid but this tends to break them and impairs controlover pellet size obtained by injecting the colloidal solution under thesuriace of the liquid. It must be borne in mind that considerableshrinkage takes place. not only by syneresis, but also during dryin andControl oi giobule size must take into account this shrinkage.

The size of the globules is controlled by the rate at which thecolloidal solution flows through the noule oriiice and the dimensions ofthe latter. A simple ,modiilcation in controlling the size at theglobules isthe introduction 01' a bam e Just outside of the nozzle mixerand in the stream of the colloidal solution. Furthermore, sizing is amatter of relative densities and viscosities of the colloidal solutionand water-immiscible liquid.

In the mixing nozzle ll. solutions to be mixed are metered accuratelyand then admitted through lines I! and it to a chamber which has a rotorll rotated by shaft 20 at a speed 01' at least about 1700 R. P. M. froma source of power not shown. The rotor i8 is constructed from arectangular bar of metal whose edges are rounded oi! in such manner thatthe walls or the mixing chamber serve as a guide for them. The roundededges of the rotor are grooved; thus, emcient dispersion both solutionsin each other is maintalned and gel formation is prevented in the mixingnozzle. The rotor may be fluted in any suitable manner or provided withother inequalities of surface to increase agitation in the mixing zone.Helical grooves for such purpose are shown on the rotor Ii of themodified form of mixing nozzle illustrated diagrammatically in Figure 2.The best operation 0! the mixing nozzle is realized when the rates ofthe reactant solutions are so high that the time the latter solutionsspend in the mixing chamber is only a very small fraction 01' thegclation time.

A further modification is the extremely simple mixer oi. Figure 3wherein the rotor 22 is merely a shaft which may be fluted, groovedaetc.

Another modification that may be applied to any of the mixing nozzlesillustrated in Figures 1, 2 and 3 is to provide means for inJecting airinto the solutions admitted to the mixing chamber or to the mixingnozzle itself. By this means, hydrogel pellets are obtained whichcontain numerous small bubbles of air which serve to make the processeddry gel less dense in nature and more porous.

The apparatus of Figure 4 is adapted for upward now of the colloidalsolution during gelation. In this case, the mixing nozzle 18 ispositioned at the bottom of shell II which contains a column ofwater-immiscible liquid heavier than water, with water thereabove, theliquidliquid interface being again indicated at H. Water is admitted bya pipe 28 while water carrying gelled spheroids is withdrawn bydischarge line 24.

A peculiar feature of the present gel pellets is theirtransparency-having the appearance or clear glass beads, in many cases.This appearance is retained only when silica is predominant, thetransparency being lost as content of other oxides is increased. Forexample, 25% thoria or 15% alumina are about the upper limits for glassyappearance of sillca-thoria and silicaalumina gels, respectively, whenprepared from colloidal solutions having a pH below 8. At a pH above 8,white translucent gels are produced, even from pure silica.

The present pellets are extremely hard and, due to this property andtheir smooth surfaces, are capable oi resisting losses by attrition andshock in handling for periods many times longer than the molded pelletsused heretofore.

trample I solution of sodium silicate containing grams oi 810: per literwas prepared by diluting N" brand oi sodium silicate (28.7% SiOs, 8.0%No.10). This solution was mixed with a second solution containing 84.10grams of AhiBOd: and 25.05 grams of 11:80: per liter at the ratio of1.00 volume of the former solution to 0.780 volume of the latter. Theresulting colloidal solution leaving the mixer through orifices wasintroduced into the top of a column of gas oil whose depth was eightfeet. The globules of solution fell through the oil and gelled beforepassing into the layer of water located beneath the oil. The gel in theglobular form was conducted out of the bottom oi the column in a streamof water and on removal from the water, it was washed with petroleumnaphtha to remove oil from its surface. It was then washed with waterand NHtCl solution, to replace zeolitically held sodium ions by ammoniumions which are capable of being driven oi! as NH: gas by heat. The gelwas dried slowly and uniformly at F. until shrinkage was substantiallycomplete and the drying was continued at a gradually-increasingtemperature up to 1050 F. at which temperature it was maintained for twohours. The silica-alumina gel retained its spheroidal shape during thewashing and drying operations.

Alternatively, the hydrogel pellets may be dried without shrinkage byreplacing the liquid phase, water, with a liquid of relatively lowcritical temperature, such as alcohol, heating to the criticaltemperature while maintaining pressure sumcient to maintain the alcoholliquid and permitting vaporization of the alcohol at a temperature abovethe critical.

The time of gelation for the concentrations and proportions of reactantsgiven above was about ten seconds, while the pH was 6.9. The gas oilemployed was a fraction of Oklahoma City gas oil having a boiling rangeof 471 to 708' I and a specific gravity of 0.846.

Example II This example illustrates the use of chlorobenzene as a fluidmedium and the mixing of reactants at such concentrations andproportions that the gelation time was approximately twenty secondswhile the pH was 6.9. Since chlorobenzene has a density of 1.101, thecolloidal solution was elected into the bottom of a ten foot column ofchlorobenzene (see Fig. 4), the globules of solution rose through thefluid and gelled before passing into a layer of water contained over thechlorobenzene. The gel was washed and dried as described in Example I(the washing with petroleum naphtha was unnecessary here).

The sodium silicate solution contained 105 grams of $10: per liter(prepared from N brand sodium silicate) while the second solutioncontained 27.10 grams AMSOO: and 19.95 grams of H280; per liter. Thesesolutions were mixed at a ratio of 1.00 volume of the former solution to0.980 volume of the latter,

trample ff! This example iiiustratu the preparation ofspherically-shaped silica gel pellets and theconversionoftheseintoacrackingoltalylt. The time of gelation for theconcentrations and proportions of reactants given below was about thirtyseconds while the pH was 5.7.

The apparatus shown diagrammatically in Fig.- ure 1 was employed in themanufacture of the silica hydrogel. A solution of sodium silicatecontalning 106.3 grams of B10: and 83.0 grams of Nero per liter.prepared by diluting "N" brand of sodium silicate, was meteredaccurately and admitted continuously to the mixing chamber by inlet iswhile a metered solution of 3.90 normal hydrochloric acid wascontinuously fed at inlet H. The reactant solutions were mixed at aratio of 3.34 volumes of the sodium silicate solution to 1.00 volume ofthe acid solution. The resulting colloidal solution leaving the mixerentered at the top of a nine-foot column of petroleum oil having aviscosity of 305 Baybolt seconds (100 1".) and a density of 0.891. Theglobules of solution fell through the oil and gelled before passing intothe layer of water located beneath the oil. The spherically-shapedhydrogel was conducted out of the bottom of the column ii in a stream ofwater by means of conduits I4 and I. The bydrogel was washed withbenzene to remove the film of oil and then washed with water until freeof sodium chloride. The washed hydrogel was soaked overnightin a 25%solution of and then the excess solution was poured off. Thespehrically-shaped silica hydrogel impregnated with aluminum nitrate wasdried slowly at 180 1''. until shrinkage was substantially complete andthe drying was continued at a gradually-increasing temperature up to1050" F. at which temperature it was maintained for two hours. Thealuminum nitrate was converted to the oxide dur-' ing the heatingprocess, and thus a silica-alumina gel catalyst in the form ofspherically-shaped pellets was obtained having good activity as acracking catalyst.

The hydrogel globules prepared in Examples 1, 2 and 3 were of about 5millimeters in diameter and no dimculty was encountered in drying andshrinking these to their normal form. It has been found, however, thatwith hydrogel globules of the order of 8 or 10 millimeters in diameterconsiderable cracking and splitting of the globules takes place whenthey are dried rapidly: this may be overcome by treating the globuleswith boiling water or steam for at least to 30 minutes prior to drying.

The spherical pellets of Example 1 have been compared by hardness teststo pellets formed in conventional manner. A comparison on crackingefilclency shows the present pellets to have substantially the sameeflect as molded pellets and broken fragments. A silica-alumina hldrogelwas prepared by mixing reagents of the same concentration and in thesame proportions as in Example I. This was permitted to gel as a mass inconventional manner.

The hydrogel, after being washed, was divided into two portions, the onepart was dried. then crushed to produce fragmentary pieces of thedesired size; the other portion of the hydrogel was cast into molds anddried, thus forming small cylindrical pellets. These two forms of gelwere subjected to a hardness test developed for cracking catalysts whichconsists of tumbling an 80 cc.

assaoaa sample of material in a one-pound grease can with one x 8%"Monel metal rod at 80 R. P. M. on a paint roller mill for a period ofone hour, then screening the sample to determine the quantity which haspowdered and broken down to a size smaller than the original. Thefragmentary pieces of gel showed a breakdown of 12%, while thecylindrical pellets were broken down to the extent of 6%. The largerbreakdown with the gel in the fragmentary form is probably due to theirregular shapes and to the stresses and fissures developed during thecrushing operation.

The spherically-shaped gel of Example 1 under the above conditions ofhardness test gave no Powdering nor breakdown. Continuing the test foran additional 15 hours merely scratched the surface of the spheres, thusproducing only a negligible amount of fines. subjecting the gel to thehardness test for a total of eighty hours gave 0.3% of material whichwas smaller in size than the original.

The pellets of this invention may act as carriers for other material inthe manner well known in the art.

The gel pellets of the present invention vary in size according to thedegree of subdivision of the colloidal solution which is, in turn, afunction of several variables. the most important being manner ofsupplying the colloidal solution and surface tension at tlm interfacebetween colloidal solution and the immiscible liquid to which it issupplied. Size of the pellets will also be affected by the manner ofdrying, it appearing that shrinkage during drying is due to capillaryaction at the meniscus of the liquid phase as it retreats through theporous gel structure. Pellets as large as desired can be prepared: butfor most purposes, particularly for catalytic hydrocarbon converslon,maximum sizes are about 10 ms. in diameter. Preferably, the pellets areabout 3 to 7 ms. in diameter, while present indications are that 5 mm.particles are of general application.

The pellets are generally spheroidal in shape, usually being somewhatflattened to forms approximating ellipsoids. Th irregularity of theshapes and sizes under methods of commercial production are stronglyreminiscent of the rounded pebbles in the bed of a water course; thoughthe pellets are, of course, much smaller. For that reason, the bestdefinition of shape seems to be "rounded pellets" designating solidswhich are bounded substantially solely by smooth curves, and havingsubstantially no plane or angular faces. The surfaces of the pellets, inaddition to being made up of smooth curves, are usually lnherentlysmooth themselves: being similar to a glass in smoothness and luster atsurfaces resulting from formation as contrasted with fracture surfaces.The resemblance to glass is further intensified by the nature of thefracture and the power to transmit visible light. The fracture ischaracteristically conchoidal and the pellets are transparent totranslucent, depending upon the mode of formation; 1. e., concentrationand pH of colloidal solution, history of treatment, etc. This is inmarked contrast to the molded synthetic gel pellets which areessentially chalky in appearance and physical characteristics, althougha little harder than chalk.

The surfaces (both original and fracture surfaces) of the presentpellets are extremely hard in view of the chemical and physical naturethereof. Precipitated silica is normally soft and the highly porousnature of the pellets leads to an expectation that the pellets wouldhave easily scratched surfaces. Surprisin ly. the surfaces havehardnesses on the order of that of glasses. The preferred types vary inhardness irom slightly less than 4 on Mobs scale to 6 and harder,usually around 5. Pellets are readily obtained on a commercial scalecapable of scratching annealed glass such as Pyrex. The advantages ofsuch hardness are obvious. particularly when coupled, as in the presentcase with a smooth suriace. when used for catalytic conversion ofhydrocarbons, for example, particles of catalytic material are eitherpacked in a stationary bed, passed continuously as a moving columnthrown a treating chamber, or suspended in the gaseous material to becontacted. In the continuous the particles are in constant motion andsubjected to constant abrasion. Smooth, hard surfaces, such as those ofthe present pellets, resist abrasion: while the sort rough surfaces ofthe particles used by the prior art break down rapidly producingundesired iines andusingupthecatalyst. llveninstationary bed operation,the pellets are subjected to destructive forces. The pellets must betransported toandplacedlntheapparahisanddurlngoperation, flowing gasesand fluctuating prusures resuit in undesirable attrition.

The strength of the pellets is extremely high. Individual particles.prepared in the manner described above, support well over 50 pounds.This is determined by placing a single pellet on an anvil and applyingforce directly to the upper surface of the pellet until it crushes.Individual pellet strengths in excess of 100 pounds are preferred andstrengths of 350 pounds are not unusual in normal pellets prepared asdescribed. A contrast with molded pellets of the same chemicalcomposition is helpful. As prepared commercially, these molded pelletscrush under a weight of about ll pounds. By melding under high pressureit is possible to achieve a strength of about pounds maximum, butpressure molding is not commercially feasible. The crushing strength ofthe pellets in mass is also extremely high. Normal pellets of thisinvention will withstand (in mass) upwards of 1000 pounds per squareinch and it is preferred that the mass of pellets be capable ofwithstanding at least 2000 pounds per square inch. Batches have beenprepared of pellets which, in mass, withstand pressures of 3000 poimdsper square inch or more. For purpose of comparison, it is noted thatcommercial molded silica gel catalyst in mass crushes under pressures of500 pounds per square inch, while fragmentary particles of silica gelcatalyst in mass crush under pressures of 100 pounds per square inch.

Internally, the present gel pellets have substantially the structure ofthe original hydrosel with the liquid phase removed. The size of thepellet is, of course, reduced in normal drying and the structure isprobably slightly deformed to a degree commensurate with deformation ofthe pellet as a whole. For all practical intents and purposes, however,the original gel structure is completely retained by the dried pellets.It is a necessary corollary of this fact that the finished gel pelletsare uniformly porous as contrasted with molded pellets wherein someportions are badly deformed by the molding operation to largelyeliminate a portion of the porous structure.

The apparent density of the product varies in the same direction as thecrushing strength. but the strength is not simply a tunction oi apparentdensity. By the term "apparent density,"referenceismadetoweight.ascomparedwiththe volume occupied by a mass ofthe particles. It is determined by weighing a fairly large volume ofarticles. For example, a large diameter graduated cylinder W to a volumecalibration and the weight of pellets determined by diflerence in weightof the graduate before and after filling with pellets. In general,apparent density of the present pellets varies between 0.5 and 1.1 gramsper cc. Lighter pellets having apparent densities as low as 0.3 gram percc. can be prepared but their hardness and crushing strength are low.Apparent densities above about 0.7 gram per cc. are preferred. Bycomparison. molded gel catalyst usually has an apparent density around0.55 gram per cc. Higher densities, up to about 0.75 gram per cc. arepossible with high pressure molding. An interesting interdependence ofapparent density and composition of the gel pellets has been noted. whensilica-alumina gels are prepared by mixing sodium aluminate, water glassand a mineral acid, increased apparent densities permit lowering of thealumina content for equal activities. Strangely, this rule does notapply if the colloidal solution to be gelled is obtained by mixingaluminum sulfate and water glass to obtain a colloidal solution of thesame pH, silica content and alumina content. The table below shows thestrange relationship noted above. The table shows activities (per centconversion of a standard charge to gasoline under standard conversionconditions) of a number of AlzOa-SlO: gel cata- Another eilect oidensity is in controlling temperatures of the catalyst mass in use. Inregenerating spent hydrocarbon conversion catalysts, carbonaceousdeposits are burned off with preheated air. Provision must he made forsome means to abstract heat from this hishly exothermic reaction toprevent damage to the catalyst. The more dense catalysts have a higherheat capacity per unit volume and are thus able to abmrb more heatthemselves without suffering heat damage, thus decreasing the load onother heat-controlling means in the system.

As noted above, the present pellets are very well suited to bed-in-plaoeoperations of the type described in the patents to Eugene J. Houdry andassociates. Much greater advantages are realised, however. in continuousoperation in apparatus for passing the catalyst cyclically throughconversion and regeneration zones; for example, the appsratus of Figures5 and 6.

In Figure 5, character M denotes a regeneration chamber, II a purginsection, I: a reaction cham. ber, 88 a second purging section, and 34 anelevator for catalyst particles. Regeneration chambcr I0 and reactionchamber 32 are similar in construction and internal nttings and consist(reierring now to 3B), of an exterior shell ll, which may be cylindricalor rectangular in cross-section, with a convergent sealed top II and aconvergent bottom 38, and fitted with an interior raise bottom 86, whichis perforate, the perforations there in being too small for the passageof catalyst particles but permitting the passage of liquid or gas.Bottom 35 is fitted with pipe 31, and top H with pipe 38. At the top orII is a sealed feeding device 89, which may be a star wheel as shown. anintermittently operated valve set-up or other common device or thisnature. Catalyst material introduced through 39 illls the interior ofshell ill, passes down therethrough. is collected by ialse bottom 38 andshute l and is removed by a second intermittently operating device, suchas star wheel ll. This arrangement eil'ects a. continuously movingstream 01 catalytic material through shell III. Reaction mixture, inthis case air ior an oxidizing regeneration, may be introduced throughpipe 31 and products of reaction, in this case flue gas, may be removedthrough pipe 38. This effects a continuously flowing stream oi reactionmaterial in physical contact with the continuously flowing stream ofcatalytic material in shell Ill. The flow shown is countercurrent. Ifdesired, it may be made concurrent by reversing the functions of 81 and38. Shell 32 is similarly fitted and similarly operated. Reactionmaterial,

in this case hydrocarbons, is introduced by H, and removed by .3,catalyst movement is controlled by and 45. Confined passage 3|,maintained relatively full of catalyst by devices ll and M, is fittedwith pipes IO and 41, by means of which steam may be passed through thecatalyst for purging. A similar purging passage II lies below shell 82,is controlled by devices ll and ll and fltted with steam pipes II and Itfor purging catalyst after reaction. From I: the catalyst drops through48 into boot II or elevator 84 by which it is elevated and dischargedinto bin II above shell 36. Elevator 30 may be of the belt and buckettype shown or or any other kind suitable for the physical properties ofthe catalytic materials. Customary devices tor the removal of fines andthe addition 01' makeup may be inserted in the catalyst conveyor system.

Turning to Figure 6, which shows an operating set-up appropriate for aconversion of hydrocarbons, such as. for example, a vapor phasecracking, charge oil is fed through pipe I by pump 55 to a vaporpreparation unit it. Vapor preparation unit It will consist essentiallyof a heater, ior which purpose any 01' the usual forms of heater commonin the art, say a pipe still, may be used, to heat and vaporize thecharge and heat it to reaction temperature, and, if the charge used isnot wholly vaporized at the reaction temperature, a vapor separator toremove unvaporized liquid residue. Vapors from II move through pipe 67into and through reaction chamber 58, (the same as II, Figure 5) andtherein undergo catalytic reaction. Reaction products pass through pipeis to product purification and recovery equipment denoted by '0. Element'0 may be made up of any or the usual fractionation, separation, anddisposal devices currently in common use for handling products ofcracking reactions. 11 desired, product fractions boiling above thedesired low-boiling product may be returned to the system forretreatment, either separately or in admixture with fresh charge.Catalytic material flowing from It is purged in II and elevated by 82 tobe introduced into a 10 Oil 1 WBUBI.

(cold volumes), at a temperature of 800' l". was contacted with acatalyst oi activated gel pellets at a rate of one volume or oil (cold)to tour volumes of catalyst in a chamber through which the catalystpassed at such a rate that it remained in the reaction zone about 20minutes, with the following results:

Yield of 410' E. P. gasoline (including isobutane and heavier in gas)volume, per cent- 67.4 Yield of dry gas (lighter than isobutane) weight.per cent..- 4.0 Yield of coke -weight, per cent 2.5 Yield of recyclestock -volume, per cent 35.0

In this run the catalyst was passed through the regeneration chamber (0!the same size as the reaction chamber) at the same rate, and was burnedwith a suiilcient volume or air to maintain above 10% GO: in the exitflue gas.

The gasoline produced was of excellent quality, high in anti-knockrating, and the recycle stock was clean, light in color, and of aboutthe same boiling point as the charge. No high boiling, dirty, liquidcracking tar was produced. The regenerated catalyst was equal ineiilciency to new catalyst, no detectable deterioration in quality beingfound.

I claim:

1. In a process for the manuiacture oi valuable hydrocarbon products bycontacting reactants containing carbon and hydrogen with an inorganicsynthetic gel, the improvement which comprises contacting said reactantsat conditions of temperature and pressure suitable for the process withhard homogeneous porous dried particles 01' said gel bounded by smoothhard glossy surfaces consisting substantially of smooth curves andcharacterised by a high resistance to attrition loss. said particleshaving been produced by a process which comprises forming a hydrosol ofinorganic oxide characterized by an inherent capacity to set to ahydrogel upon the lapse of a suitable period or time without addition toor subtraction from said gel or any substance, admitting said sol in theform or separate globules to a body of a fluid medium substantiallyimmiscible with water in which said globules assume spheroidal shape dueto surface tension at the interface between said sol and said medium,retaining said spheroidal globules in said medium until gelation occursthus rorming spheroids or hydrogel, eflecting retention in said sol ofsubstantially all the constituents or said sol until gelation occurs anddrying the hydrogel spheroids.

2. In a process for the manufacture of valuable hydrocarbon products bycontacting reactants containing carbon and hydrogen with an inorganicsynthetic gel containing silica, the improvement which comprisescontacting said reactants at conditions or temperature and pressuresuitable for the process with hard homogeneous porous dried particles ofsaid gel bounded by smooth hard glossy surfaces consisting substantiallyof smooth curves and characterized by a high resistance to attritionloss, said particles having been produced by a process which comprisesforming bounded by smooth hard glossy surfaces consisting substantiallyof smooth curves and characterized by a high resistance to attritionloss, said particles having been produced by a process which a hydrosolof inorganic oxide including silica 5 comprises forming a hydrosol ofinorganic oxide characterized by an inherent capacity to set to acharacterised by an inherent capacity to set to a hydrogel up n thelapse of a suitable period of hydrogel upon the lapse of a suitableperiod of time without addition to or subtraction from said time withoutaddition to or subtraction from said gel of any substance, dm ing saidsol in the gel of any substance. admitting said sol in the form ofseparate globules to a body of a fluid me- 10 form of separate globulesto a body of a fluid medium substantially immiscible with water in whichdium substantially immiscible with water in which said globules assumespheroidal shape due to sursaid globules assume spheroidal shape due tosurface tension at the interface between said sol and face tension atthe interface between said sol and said medium. retaining s idspheroidal globules in said medium, retaining said spheroidal globulessaid medium until gelation occurs thus forming is m i medium ti l tioccurs t forming spheroids 0! hydro l. eff s retention in said spheroidsof hydrogel, eflecting retention in said sol of substantially all theconstituents oi said sol of substa tially l th n t t t of said so] untilgelation occurs and drying the hydrogel m gelation mm and drying thydrogel spheroids. spheroids.

3. In a process of contacting a hy r n 5. In aprocess for modifying ortreating a fluid fluid with an inorganic synthetic gel, the improvebycontacting aid fluid it an inorganic syn.- ment which comprisescontacting said hydrocarm t; gel containing silica under treating -11-bon fluid with hard h mo eneous porous dried tions adapted to cause thedesired eflect on said particles of said gel o n d by Smooth hard fluidwithout substantial change in structure or glossy surfaces consistingsubstantially of smooth as chemical nature a! said gel other thanaccumucurves and characterized by a high resistance to laflon in saidgel of substances removable by attrition loss, said parti l ins beenProduced generation to restore the condition of said gel; by a processwhich comprises forming a hydrosoi the impmvement m comprises contactingsaid of inorganic oxide characterized by an inherent fluid at conditionsof temperature and pressure c paci y to Set t B hydroflel D the lapsesuitable tor the process with hard homogeneous a suitable period of timewithout addition to or porous dried a of said gel bounded by subtractionfrom sa d 8 1 of y Substance. smooth hard glossy surfaces consistingsubstanmitting said sol in the form of separate globules any f smoothcurves and characterized by a to a body of a fluid medium substantiallylmrnism r sistance m tt t 1038, said particles cible with water in whichsaid globules assume to having been produced by a process whichspheroidal shape due to surface tension at the inprises forming ahydrosol of inorganic oxide ter m between said 501 and mediumeludingsilica characterized by an inherent cataining said spheroidal globulesin said medium to set to a hydrogel upon the lapse of until gelationoccurs thus forming sph of suitable period of time without addition toor hydros l. 81180111118 retention in said of a subtraction from saidgel of any substance, adstantiaily all the constituents of said soluntil muting said 901 in the tom of separate globuies gelation occursand drying the Yams! sphe' to a body of a fluid medium substantiallyimmismlds' cible with water in which said globules assume In a processfor modlfyim! treating a fluid spheroidal shape due to surface tensionat the mby contaotlns sold fluid with an inorgamc terrace between saidsol and said medium, rethetic gel under treating conditions adapted totame. said spheroidal globules in said medium cause the desired effecton said fluid without submm gelation occurs thus fomlng spheroids gstantiai change in structure or chemical nature hydrogel' effectingretention m said 601 of or sai sel other than wwmulmc'n said stantiallyall the constituents of said sol until of substances removable byregeneration to re- 80 gelation occurs and drying the hydro; sphestorethe condition of said gel; the improvement which comprises contactingsaid fluid with hard homogeneous porous dried particles of said gelroids.

MILTON M. MARISIC.

CERTIFICATE OF CORRECTI ON a Patent No. 2.5%,91 2. September 18, 1915.

MILTON M. MARISIC- It is hereby certified that error appears in dieprinted specification of the above numbered patent requiring correctionas follows: Page 14., first column, line 50, for "normal" read--ii.na1-; line 65, "lildrogel" read --hydrogel--: and that the saidLetters Patent should be read with his correction therein that the samemay conform to the recorder th e in the Patent Office.

Signed and sealed this 9th day of April, A. 1). 19%.

Leslie Frazer (Seal) First Assistant Commissioner of Patents.

aces-.042

hard glossy surfaces consisting substantially of smooth curves andcharacterized by a high resistance to attrition loss, said particleshaving been produced by a process which comprises forming a hydrosol ofinorganic oxide including silica characterized by an inherent capacityto set to a hydrogel upon the lapse of a suitable period of time withoutaddition to or subtraction from said gel of any substance, admittingsaid sol in the form of separate globules to a body of a fluid mediumsubstantially immiscible with water in which said globules assumespheroidal shape due to surface tension at the interface between saidsol and said medium, retaining said spheroidal globules in said mediumuntil gelation occurs thus forming spheroids oi hydrogel, eflectingretention in said sol of substantially all the constituents of said soluntil gelation occurs and drying the hydrogel spheroids.

3. In a process of contacting a hydrocarbon fluid with an inorganicsynthetic gel, the improvement which comprises contacting saidhydrocarbon fluid with hard homogeneous porous dried particles of saidgel bounded by smooth hard glossy surfaces consisting substantially ofsmooth curves and characterized by a high resistance to attrition loss,said particles having been produced by a process which comprises forminga hydrosol of inorganic oxide characterized by an inherent capacity toset to a hydrogel upon the lapse of a suitable period of time withoutaddition to or subtraction from said gel of any substance, admittingsaid sol in the form of separate globules to a body of a fluid mediumsubstantially immiscible with water in which said globules assumespheroidal shape due to surface tension at the interface between saidsol and said medium, retaining said spheroidal globules in said mediumuntil gelation occurs thus forming spheroids of hydrogel, efl'ectingretention in said sol of substantially all the constituents of said soluntil gelation occurs and drying the hydrogel spheroids.

4. In a process for modifying or treating a fluid by contacting saidfluid with an inorganic Synthetic gel under treating conditions adaptedto cause the desired effect on said fluid without substantial change instructure or chemical nature of said gel other than accumulation in saidgel of substances removable by regeneration to restore the condition ofsaid gel; the improvement which comprises contacting said fluid withhard homogeneous porous dried particles of said gel bounded by smoothhard glossy surfaces consisting substantially of smooth curves andcharacterized by a high resistance to attrition loss, said particleshaving been produced by a process which comprises forming a hydrosol ofinorganic oxide characterised by an inherent capacity to set to ahydrogel upon the lapse of a suitable period of time without addition toor subtraction from said gel of any substance. admitting said sol in theform of separate globules to a body of a fluid medium substantiallyimmiscible with water in which said globules assume spheroidal shape dueto surface tension at the interface between said 501 and said medium,retaining said spheroidal globules in said medium until gelation occursthus forming spheroids of hydrogel, eflecting retention in said sol orsubstantially all the constituents of said sol until gelation occurs anddrying the hydrogel spheroids.

5. In a process for modifying or treating a fluid by contacting saidfluid with an inorganic syn-- thetic gel containing silica undertreating conditions adapted to cause the desired eflect on said fluidwithout substantial change in structure or chemical nature of said gelother than accumulation in said gel of substances removable byregeneration to restore the condition of said gel; the improvement whichcomprises contacting said fluid at conditions of temperature andpressure suitable tor the process with hard homogeneous porous driedparticles of said gel bounded by smooth hard glossy surfaces consistingsubstantially of smooth curves and characterized by a high resistance toattrition loss, said particles having been produced by a process whichcomprises forming a hydrosol of inorganic oxide including silicacharacterized by an inherent capacity to set to a hydrogel upon thelapse of a suitable period of time without addition to or subtractionfrom said gel of any substance, admitting said sol in the form ofseparate globules to a body of a fluid medium substantially immisciblewith water in which said globules assume spheroidal shape due to surfacetension at the interface between said sol and said medium, retainingsaid spheroidal globules in said medium until gelation occurs thusforming spheroids of hydrogel, eflectlng retention in said sol ofsubstantially all the constituents of said sol until gelation occurs anddrying the hydrogel spheroids.

MILTON M. MARISIC.

CERTIFICATE OF CORRECTI 0N Patent No. 2.38 a9h2.

MILTON n. muusrc.

September 18, 1913.5.

It is hereby certified that error appears in ins printed specificationof the above numbered patent requiring correction as follows: Page 14.,first column, line 50, for "normal" read --ii.na1 --hydrogel--: and thatthe said Letters Patent should be read with his correction therein thatthe some may conform to the recorder th e in the Patent Office.

line 65, for "lildrogel" read Signed and sealed this 9th day of April,A. o. 19h6.

(Seal) Leslie Frazer First Assistant Commissioner of Patents.

